Reduced calorie center-filled chewing gum compositions having improved stability

ABSTRACT

The present invention pertains to a center-filled chewing gum composition having an outer shell enclosing a cavity and a liquid center within the cavity, wherein the outer shell comprises a gum base having an enhanced hydrophilic nature. In a preferred embodiment invention pertains to a center-filled chewing gum composition wherein the outer shell comprises a gum base comprising in percentages by weight of the gum base (a) an elastomer present in an amount from about 0.5% to about 20%, (b) a medium molecular weight polyvinyl acetate polymer having a molecular weight from about 35,000 to about 55,000 present in an amount from about 10% to about 25%, (c) an acetylated monoglyceride present in an amount from about 4.5% to about 10%, (d) a wax having a melting point below about 60° C. present in an amount from about 6% to about 10%, and (e) a component selected from the group consisting of elastomer solvents, emulsifiers, plasticizers, fillers, and mixtures thereof, present in an amount to bring the total amount of gum base to 100%. The center-filled chewing gum compositions may be used with a wide variety of liquid centers. The present invention also pertains to methods for preparing the center-filled chewing gum compositions.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of application Ser. No.939,918, filed Dec. 10, 1986 now U.S. Pat. No. 4,872,884.

FIELD OF THE INVENTION

This invention pertains to a center-filled chewing gum compositionhaving improved stability. More particularly, this invention pertains toa chewing gum having an improved outer shell enclosing a cavity and aliquid center-fill within the cavity, wherein the outer shell comprisesa high gum base composition having an enhanced hydrophilic nature. Theimproved outer shell of the center-filled chewing gum compositions maybe used with a wide variety of liquid center-fills to help retain thefluid in the cavity. The present invention also pertains to methods forpreparing the improved center-filled chewing gum compositions.

DESCRIPTION OF THE PRIOR ART

Center-filled chewing gum compositions are well known in the art. Ingeneral, such gums consist of an outer shell having a chewing gumcomposition enclosing a cavity containing a liquid center-fill whichcontains various additives such as flavoring agents, sweetening agents,and the like.

Maintaining the integrity of the liquid center and solid outer shell isa frequently encountered problem with center-filled chewing gumcompositions during storage. One stability problem with center-filledchewing gum compositions is that on storage the liquid center tends tobe absorbed by, or migrates into, the solid outer shell which results ina gum composition which has a softer outer shell and a reduced liquidcenter. A stability second problem with center-filled chewing gumcompositions is that on storage ambient moisture is absorbed into theouter shell causing the outer shell to soften. Attempts to improve thestorage stability of center-filled chewing gums have focused mainly onmodifying the composition, and minimizing the aqueous content, of theliquid center to retard migration and absorption of the liquid into theouter shell. In general, only small amounts of a liquid center (up toabout 20% by weight) have been incorporated into center-filled chewinggums.

U.S. Pat. No. 3,894,154, issued to Graff et al. and assigned toWarner-Lambert Company, discloses a center-filled chewing gum whichcontains an aqueous liquid center containing a water-miscible humectantsuch as glycerin to reduce the moisture content of the center and tothereby retard an increase in viscosity of the liquid center.

U.S. Pat. No. 4,156,740, issued to Glass et al. and assigned toWarner-Lambert Company, discloses a sugarless center-filled chewing gumwhich contains an aqueous liquid center containing a natural orsynthetic gum such as carboxymethyl cellulose to bind the water in theliquid center.

U.S. Pat. No. 4,157,402, issued to Ogawa et al. and assigned to LotteCo., Ltd., discloses a center-filled chewing gum which contains anaqueous liquid center containing an emulsifier to bind the flavor oilsand water thereby reducing separation and migration of the center.

U.S. Pat. No. 4,316,915, issued to Friello et al. and assigned to LifeSavers, Inc., discloses a center-filled chewing gum which contains aliquid center containing a thickener such as carboxymethyl cellulose insubstantially all glycerin to retard migration of the liquid center intothe outer shell.

U.S. Pat. No. 4,466,983, issued to Cifrese et al. and assigned toWarner-Lambert Company, discloses a center-filled chewing gum whichcontains a liquid center containing a mixture of hydrogenated starchhydrolysates, sorbitol solution, glycerin and optionally a flavoringagent, wherein the total water content of the liquid center is about 5%or less.

U.S. Pat. No. 4,698,223, issued to Perfetti et al. and assigned to GumBase Co., SPA, discloses a no-calorie chewing gum composition whichcomprises from 92% to 99% of a gum base, up to 4% of glycerol, and up to3% of a flavoring agent. The gum base comprises from 8% to 15% of anelastomer, from 10% to 30% of a hydrogenated or partially hydrogenatedanimal or vegetable oil, from 10% to 39% of an inert mineral filler,from 8% to 25% of polyvinyl acetate, from 4% to 9% of fatty acidglycerides, from 15% to 25% of resins, from 2% to 6% of natural gum,from 4% to 12% of wax and up to 0.05% of antioxidants.

While the above center-filled chewing gum compositions provide gumshaving improved stability during storage, none of the above compositionsprovides a center-filled gum composition which can accommodate a widevariety of liquid center compositions. Accordingly, it would becommercially advantageous to provide a center-filled chewing gum whichcan be used with a variety of liquid centers, which can encapsulate asubstantially all aqueous liquid center, and which can accommodate aliquid center in an amount above 20%. The present invention providessuch an improved center-filled chewing gum product without thedisadvantages characteristic of previously known products. Inparticular, the present invention provides a center-filled chewing gumcomposition containing a high gum base outer shell which may be usedwith a wide variety of liquid center-fills to help retain the fluid inthe cavity and prevent the liquid from being absorbed into the outershell. The present invention also pertains to methods for preparing theimproved center-filled chewing gum compositions.

SUMMARY OF THE INVENTION

The present invention pertains to a center-filled chewing gumcomposition having an outer shell enclosing a cavity and a liquid centerwithin the cavity, wherein the outer shell comprises a gum base havingan enhanced hydrophilic nature. In a preferred embodiment the inventionpertains to a center-filled chewing gum composition wherein the outershell comprises a gum base comprising in percentages by weight of thegum base (a) an elastomer present in an amount from about 0.5% to about20%, (b) a medium molecular weight polyvinyl acetate polymer having amolecular weight from about 35,000 to about 55,000 present in an amountfrom about 10% to about 25%, (c) an acetylated monoglyceride present inan amount from about 4.5% to about 10%, (d) a wax having a melting pointbelow about 60° C. present in an amount from about 6% to about 10%, and(e) a component selected from the group consisting of elastomersolvents, emulsifiers, plasticizers, fillers, and mixtures thereof,present in an amount to bring the total amount of gum base to 100%. Thecenter-filled chewing gum compositions may be used with a wide varietyof liquid centers. The present invention also pertains to methods forpreparing the center-filled chewing gum compositions.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts in graphic format the moisture absorption, in percentagemoisture absorbed by weight versus weeks of storage, of the chewing gumcomposition of examples 1-2 (controls) and examples 3-7 (test samples)at 27° C. and 80% R.H.

DETAILED DESCRIPTION OF THE INVENTION

The present invention pertains to a center-filled chewing gumcomposition having an outer shell enclosing a cavity and a liquid centerwithin the cavity, wherein the outer shell comprises a gum base havingan enhanced hydrophilic nature. In a preferred embodiment, the gum basecomprises (a) an elastomer present in an amount from about 0.5% to about20%, by weight of the gum base, (b) a medium molecular weight polyvinylacetate polymer having a molecular weight from about 35,000 to about55,000 present in an amount from about 10% to about 25%, by weight ofthe gum base, (c) an acetylated monoglyceride present in an amount fromabout 4.5% to about 10%, by weight of the gum base, (d) a wax having amelting point below about 60° C. present in an amount from about 6 toabout 10%, by weight of the gum base, and (e) a component selected fromthe group consisting of elastomer solvents, emulsifiers, plasticizers,fillers, and mixtures thereof, present in an amount to bring the totalamount of gum base to 100%, by weight of the gum base.

The present invention also pertains to a center-filled chewing gumcomposition wherein the outer shell comprises a chewing gum compositioncomprised of a high gum base-low bulking agent composition havingincreased hydrophobic properties. More particularly, the chewing gumcomposition comprises (A) a gum base present in an amount from about 40%to about 85%, by weight of the chewing gum composition, which comprises(a) an elastomer present in an amount from about 0.5% to about 20%, byweight of the gum base (b) a medium molecular weight polyvinyl acetatepolymer having a molecular weight from about 35,000 to about 55,000present in an amount from about 10% to about 25%, by weight of the gumbase (c) an acetylated monoglyceride present in an amount from about4.5% to about 10%, by weight of the gum base (d) a wax having a meltingpoint below about 60° C. present in an amount from about 6 to about 10%,by weight of the gum base, and (e) a component selected from the groupconsisting of elastomer solvents, emulsifiers, plasticizers, fillers,and mixtures thereof, present in an amount to bring the total amount ofgum base to 100%, by weight of the gum base, and (B) a bulking agentpresent in an up to about 60%, by weight of the chewing gum composition.

As used herein, the term "reduced-calorie composition" means acomposition having a caloric value two thirds or less than that of aconventional composition. The term "tight" or "rubbery" chew refers to achewing gum composition which requires a large amount of muscularchewing effort to masticate or to a composition which provides a gumbolus with high elasticity and bounce and which is difficult to deform.

Applicants have discovered a gum base containing a low melting point waxwhich does not require a high level of bulking agent to plasticize thegum base and render it soft during chewing. The novel gum base may beused at higher than normal levels in chewing gum compositions in placeof a bulking and/or a sweetening agent to prepare high base-low bulkingagent reduced-calorie gums which do not have rubbery or tight chewcharacteristics. The improved gum base possesses increased hydrophilicproperties over conventional gum bases and appears to increase in sizeduring chewing releasing flavoring and sweetening agents which wouldnormally be entrapped in the gum base while maintaining a soft chewtexture.

Applicants have also discovered that center-filled chewing gumcompositions employing a gum base having an enhanced hydrophilic naturesuch as the inventive gum base, either alone or in a high gum base-lowbulking agent gum composition, in the outer shell show greatly improvedstability during storage. While the invention is not to be limited totheoretical considerations, applicants believe that outer shellscomprising a gum base having an enhanced hydrophilic nature haveincreased hydrophobic character which resist absorption of the liquidcenter into the outer shell. At the same time, the hydrophobic film,which is low in bulking agent (carbohydrate) content, prevents ambientmoisture from being absorbed by the outer shell and the liquid centercausing the center to crystallize. Center-filled chewing gumcompositions prepared with the high base-low bulking agent outer shellcomposition are less hygroscopic (have lower moisture-pickup) and areless prone to becoming stale than conventional center-filled gumcompositions while having comparable firmness and texture. Moreover,significantly greater amounts of liquid centers, as well as liquidcenters containing greater amounts of water, may be formulated in thecenter-filled gum compositions.

The elastomers (rubbers) employed in the gum base of the presentinvention will vary greatly depending upon various factors such as thetype of gum base desired, the consistency of gum composition desired andthe other components used in the composition to make the final chewinggum product. The elastomer may be any water-insoluble polymer known inthe art, and includes those gum polymers utilized for chewing gums andbubble gums. Illustrative examples of suitable polymers in gum basesinclude both natural and synthetic elastomers. For example, thosepolymers which are suitable in gum base compositions include, withoutlimitation, natural substances (of vegetable origin) such as chicle,natural rubber, crown gum, nispero, rosidinha, jelutong, perillo, nigergutta, tunu, balata, guttapercha, lechi capsi, sorva, gutta kay, and thelike, and mixtures thereof. Examples of synthetic elastomers include,without limitation, styrene-butadiene copolymers (SBR), polyisobutylene,isobutylene-isoprene copolymers, polyethylene, and the like, andmixtures thereof.

The amount of elastomer employed in the gum base will vary greatlydepending upon various factors such as the type of gum base used, theconsistency of the gum composition desired and the other components usedin the composition to make the final chewing gum product. In general,the elastomer will be present in the gum base in an amount from about0.5% to about 20%, and preferably from about 2.5% to about 15%, byweight of the gum base.

The polyvinyl acetate polymer employed in the gum base of the presentinvention is a polyvinyl acetate polymer having a medium molecularweight, specifically, having a mean average molecular weight in therange from about 35,000 to about 55,000. This medium molecular weightpolyvinyl acetate polymer will preferably have a viscosity from about 35seconds to about 55 seconds (ASTM designation D1200-82 using a Ford cupviscometer procedure). The medium molecular weight polyvinyl acetatepolymer will be present in the gum base in an amount from about 10% toabout 25%, and preferably from about 12% to about 27%, by weight of thegum base.

The medium molecular weight polyvinyl acetate polymer may also beblended with a low molecular weight polyvinyl acetate polymer. The lowmolecular weight polyvinyl acetate polymer will have a mean averagemolecular weight in the range from about 12,000 to about 16,000. Thislow molecular weight polyvinyl acetate polymer will preferably have aviscosity from about 14 seconds to about 16 seconds (ASTM designationD1200-82 using a Ford cup viscometer procedure). The low molecularweight polyvinyl acetate polymer will be present in the gum base in anamount up about 17%, and preferably from about 12% to about 17%, byweight of the gum base.

When a low molecular weight polyvinyl acetate polymer is blended with amedium molecular weight polyvinyl acetate polymer, the polymers will bepresent in a mole ratio from about 1:0.5 to about 1:1.5, respectively.

The medium molecular weight polyvinyl acetate polymer may also beblended with a high molecular weight polyvinyl acetate polymer. The highmolecular weight polyvinyl acetate polymer will have a mean averagemolecular weight in the range from about 65,000 to about 95,000. Thehigh molecular weight polyvinyl acetate polymer will be present in thegum base in an amount up to about 5%, by weight of the gum base.

The acetylated monoglycerides in the present invention, like thepolyvinyl acetate polymer, serve as plasticizing agents. While thesaponification value of the acetylated monoglycerides is not critical,preferable saponification values are 278 to 292, 316 to 331, 370 to 380,and 430 to 470. A particularly preferred acetylated monoglyceride has asaponification value above about 400. Such acetylated monoglyceridesgenerally have an acetylation value (percentage acetylated) above about90 and a hydroxyl value below about 10 (Food Chemical Codex (FCC)III/P508 and the revision of AOCS).

The use of acetylated monoglycerides in the present gum base ispreferred over the use of bitter polyvinyl acetate (PVA) plasticizers,in particular, triacetin. The acetylated monoglycerides will be presentin the gum base in an amount from about 4.5% to about 10%, andpreferably from about 5% to about 9%, by weight of the gum base.

The wax in the gum base of the present invention softens the polymericelastomer mixture and improves the elasticity of the gum base. The waxesemployed will have a melting point below about 60° C., and preferablybetween about 45° C. and about 55° C. A preferred wax is low meltingparaffin wax. The wax will be present in the gum base in an amount fromabout 6% to about 10%, and preferably from about 7% to about 9.5%, byweight of the gum base.

In addition to the low melting point waxes, waxes having a highermelting point may be used in the gum base in amounts up to about 5%, byweight of the gum base. Such high melting waxes include beeswax,vegetable wax, candelilla wax, carnuba wax, most petroleum waxes, andthe like, and mixtures thereof.

In addition to the components set out above, the gum base includes avariety of traditional ingredients, such as a component selected fromthe group consisting of elastomer solvents, emulsifiers, plasticizers,fillers, and mixtures thereof. These ingredients are present in the gumbase in an amount to bring the total amount of gum base to 100%.

The gum base may contain elastomer solvents to aid in softening theelastomer component. Such elastomer solvents may comprise thoseelastomer solvents known in the art, for example, terpinene resins suchas polymers of alpha-pinene or beta-pinene, methyl, glycerol andpentaerythritol esters of rosins and modified rosins and gums such ashydrogenated, dimerized and polymerized rosins, and mixtures thereof.Examples of elastomer solvents suitable for use herein include thepentaerythritol ester of partially hydrogenated wood and gum rosin, thepentaerythritol ester of wood and gum rosin, the glycerol ester of woodrosin, the glycerol ester of partially dimerized wood and gum rosin, theglycerol ester of polymerized wood and gum rosin, the glycerol ester oftall oil rosin, the glycerol ester of wood and gum rosin and thepartially hydrogenated wood and gum rosin and the partially hydrogenatedmethyl ester of wood and rosin, and the like, and mixtures thereof. Theelastomer solvent may be employed in the gum base in amounts from about2% to about 15%, and preferably from about 7% to about 11%, by weight ofthe gum base.

The gum base may also include emulsifiers which aid in dispersing theimmiscible components into a single stable system. The emulsifiersuseful in this invention include glyceryl monostearate, lecithin, fattyacid monoglycerides, diglycerides, propylene glycol monostearate, andthe like, and mixtures thereof. A preferred emulsifier is glycerylmonostearate. The emulsifier may be employed in amounts from about 2% toabout 15%, and preferably from about 7% to about 11%, by weight of thegum base.

The gum base may also include plasticizers or softeners to provide avariety of desirable textures and consistency properties. Because of thelow molecular weight of these ingredients, the plasticizers andsofteners are able to penetrate the fundamental structure of the gumbase making it plastic and less viscous. Useful plasticizers andsofteners include lanolin, palmitic acid, oleic acid, stearic acid,sodium stearate, potassium stearate, glyceryl triacetate, glyceryllecithin, glyceryl monostearate, propylene glycol monostearate,acetylated monoglyceride, glycerine, and the like, and mixtures thereofWaxes, for example, natural and synthetic waxes, hydrogenated vegetableoils, petroleum waxes such as polyurethane waxes, polyethylene waxes,paraffin waxes, microcrystalline waxes, fatty waxes, sorbitanmonostearate, tallow, propylene glycol, mixtures thereof, and the like,may also be incorporated into the gum base. The plasticizers andsofteners are generally employed in the gum base in amounts up to about20%, and preferably in amounts from about 9% to about 17%, by weight ofthe gum base.

Preferred plasticizers are the hydrogenated vegetable oils and includesoybean oil and cottonseed oil which may be employed alone or incombination. These plasticizers provide the gum base with good textureand soft chew characteristics. These plasticizers and softeners aregenerally employed in amounts from about 5% to about 14%, and preferablyin amounts from about 5% to about 13.5%, by weight of the gum base.

In another preferred embodiment, the softening agent is anhydrousglycerin, such as the commercially available United States Pharmacopeia(USP) grade. Glycerin is a syrupy liquid with a sweet warm taste and hasa sweetness of about 60% of that of cane sugar. Because glycerin ishygroscopic, it is important that the anhydrous glycerin be maintainedunder anhydrous conditions throughout the preparation of the chewing gumcomposition.

The gum base of this invention may also include effective amounts ofbulking agents such as mineral adjuvants which may serve as fillers andtextural agents. Useful mineral adjuvants include calcium carbonate,magnesium carbonate, alumina, aluminum hydroxide, aluminum silicate,talc, tricalcium phosphate, dicalcium phosphate, and the like, andmixtures thereof. These fillers or adjuvants may be used in the gum basecompositions in various amounts. Preferably the amount of filler, whenused, will be present in an amount from about 15% to about 40%, andpreferably from about 20% to about 30%, by weight of the gum base.

A variety of traditional ingredients may be optionally included in thegum base in effective amounts such as coloring agents, antioxidants,preservatives, flavoring agents, and the like. For example, titaniumdioxide and other dyes suitable for food, drug and cosmeticapplications, known as F. D. & C. dyes, may be utilized. An anti-oxidantsuch as butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA),propyl gallate, and mixtures thereof, may also be included. Otherconventional chewing gum additives known to one having ordinary skill inthe chewing gum art may also be used in the gum base.

In a preferred embodiment, the invention is directed at a center-filledchewing gum composition having an outer shell enclosing a cavity and aliquid center within the cavity, wherein the outer shell comprises a gumbase comprising in percentages by weight of the gum base (a) anelastomer present in an amount from about 0.5% to about 20%, (b) amedium molecular weight polyvinyl acetate polymer having a molecularweight from about 35,000 to about 55,000 present in an amount from about10% to about 25%, (c) an acetylated monoglyceride present in an amountfrom about 4.5% to about 10%, (d) a wax having a melting point belowabout 60° C. present in an amount from about 6% to about 10%, (e) anelastomer solvent present in an amount from about 2% to about 11%, (f) aplasticizer in an amount from about 5% to about 14%, and (g) a filler inan amount from about 15% to about 40%.

The present invention extends to methods of making the improved gum basecompositions. The manner in which the gum base components are admixed isnot critical and is performed using standard techniques and apparatusknown to those skilled in the art. In a typical method, an elastomer isadmixed with an elastomer solvent and/or a plasticizer and/or anemulsifier and agitated for a period of from 1 to 30 minutes. Afterblending is complete, the polyvinyl acetate component is admixed intothe mixture. The medium molecular weight polyvinyl acetate is preferablyadmixed prior to addition of the optional low molecular weight polyvinylacetate to prevent the creation of pockets of polyvinyl acetate withinthe elastomer mixture. The remaining ingredients, such as the lowmelting point wax, are then admixed, either in bulk or incrementally,while the gum base mixture is blended again for 1 to 30 minutes.

In a preferred embodiment, the invention is directed to a method forpreparing an outer shell in a center-filled chewing gum composition,wherein the outer shell is comprised of a gum base, which comprises thesteps of (1) providing the following ingredients of the gum base inpercentages by weight (a) an elastomer present in an amount from about0.5% to about 20%, (b) a medium molecular weight polyvinyl acetatepolymer having a molecular weight from about 35,000 to about 55,000present in an amount from about 10% to about 25%, (c) an acetylatedmonoglyceride present in an amount from about 4.5% to about 10%, (d) awax having a melting point below about 60° C. present in an amount fromabout 6 to about 10%, and (e) a component selected from the groupconsisting of elastomer solvents, emulsifiers, plasticizers, fillers,and mixtures thereof, present in an amount to bring the total amount ofgum base to 100%, and (2) admixing the ingredients in step (1) to form auniform mixture.

Once prepared, the inventive gum base having an enhanced hydrophilicnature may be used directly as the outer shell of a center-filled gum,may be formulated with conventional additives to prepare a wide varietyof chewing gum compositions for use as the outer shell of acenter-filled gum, or may be stored for future use. The gum base may beused in sugar and sugarless containing chewing gum products to prepare areduced-calorie containing gum product.

Other gum bases having an enhanced hydrophilic nature and suitable foruse in chewing gum compositions in higher than conventional amounts mayalso be employed in the present invention. In general, these gum basesmay be employed in amounts up to 99%, preferably from about 40% to about95%, and more preferably from about 40% to about 85%, by weight of thechewing gum composition. Suitable gum bases having an enhancedhydrophilic nature include, for example, those disclosed in U.S. Pat.No. 4,698,223, which disclosure is incorporated herein by reference. Thegum base may be used directly as the outer shell of a center-filled gumor may be formulated with conventional additives to prepare a widevariety of chewing gum compositions for use as the outer shell of acenter-filled gum.

In one embodiment of the invention, the gum base having an enhancedhydrophilic nature is used as the outer shell of a center-filled chewinggum. Sweetening agents, flavoring agents, and the like, as set outbelow, may be included in the center-filled portion of the gum.

In another embodiment of the invention, the gum base having an enhancedhydrophilic nature is formulated with additives such as a bulking agent,a sweetening agent, a flavoring agent, and the like, to form a chewinggum composition which is used as the outer shell of a center-filledchewing gum. Additional sweetening agents, flavoring agents, and thelike, may be included in the center-filled portion of the chewing gum.The amount of gum base employed in the chewing gum composition will varydepending on such factors as the type of gum base used, the consistencydesired, and the other components used to make the final chewing gumproduct. In general, the gum base will be present in the chewing gumcomposition in an amount from about 40% to about 85%, and preferablyfrom about 50% to about 65%, by weight of the chewing gum composition.

The gum composition may include effective amounts of conventionaladditives selected from the group consisting of sweetening agents(sweeteners), plasticizers, softeners, emulsifiers, waxes, fillers,bulking agents (carriers, extenders), mineral adjuvants, flavoringagents (flavors, flavorings), coloring agents (colorants, colorings),antioxidants, acidulants, thickeners, and the like, and mixturesthereof. These ingredients are present in the chewing gum composition inan amount to bring the total amount of chewing gum composition to 100%.Some of these additives may serve more than one purpose. For example, insugarless gum compositions, a sweetener, such as sorbitol or other sugaralcohol, may also function as a bulking agent.

The plasticizers, softening agents, mineral adjuvants, waxes andantioxidants discussed above, as being suitable for use in the gum base,may also be used in the chewing gum composition. Examples of otherconventional additives which may be used include emulsifiers, such aslecithin and glyceryl monostearate, thickeners, used alone or incombination with other softeners, such as methyl cellulose, alginates,carrageenan, xanthan gum, gelatin, carob, tragacanth, locust bean, andcarboxy methyl cellulose, acidulants such as malic acid, adipic acid,citric acid, tartaric acid, fumaric acid, and mixtures thereof, andfillers, such as those discussed above under the category of mineraladjuvants.

The chewing gum composition may also contain a bulking agent. Suitablebulking agents may be water-soluble and include sweetening agentsselected from the group consisting of, but not limited to,monosaccharides, disaccharides, polysaccharides, sugar alcohols, andmixtures thereof; randomly bonded glucose polymers such as thosepolymers distributed under the tradename POLYDEXTROSE by Pfizer, Inc.,Groton, Conn.; isomalt (a racemic mixture ofalpha-D-glucopyranosyl-1,6-mannitol andalpha-D-glucopyranosyl-l,6-sorbitol manufactured under the tradenamePALATINIT by Suddeutsche Zucker), maltodextrins; hydrogenated starchhydrolysates; hydrogenated hexoses; hydrogenated disaccharides;minerals, such as calcium carbonate, talc, titanium dioxide, dicalciumphosphate, celluloses and the and the like, and mixtures thereof.Bulking agents may be used in amounts up to about 60%, and preferably inamounts from about 15% to about 60%, by weight of the chewing gumcomposition.

Suitable sugar bulking agents include monosaccharides, disaccharides andpolysaccharides such as xylose, ribulose, glucose (dextrose), mannose,galactose, fructose (levulose), sucrose (sugar), maltose, invert sugar,partially hydrolyzed starch and corn syrup solids, and mixtures thereof.Mixtures of sucrose and corn syrup solids are the preferred sugarbulking agents.

Suitable sugar alcohol bulking agents include sorbitol, xylitol,mannitol, galactitol, maltitol, and mixtures thereof. Mixtures ofsorbitol and mannitol are the preferred sugar alcohol bulking agents.

Maltitol is a sweet, water-soluble sugar alcohol useful as a bulkingagent in the preparation of beverages and foodstuffs and is more fullydescribed in U.S. Pat. No. 3,708,396, which disclosure is incorporatedherein by reference. Maltitol is made by hydrogenation of maltose whichis the most common reducing disaccharide and is found in starch andother natural products.

Suitable hydrogenated starch hydrolysates include those disclosed inU.S. Pat. Nos. 25,959, 3,356,811, 4,279,931 and various hydrogenatedglucose syrups and/or powders which contain sorbitol, hydrogenateddisaccharides, hydrogenated higher polysaccharides, or mixtures thereof.Hydrogenated starch hydrolysates are primarily prepared by thecontrolled catalytic hydrogenation of corn syrups. The resultinghydrogenated starch hydrolysates are mixtures of monomeric, dimeric, andpolymeric saccharides. The ratios of these different saccharides givedifferent hydrogenated starch hydrolysates different properties.Mixtures of hydrogenated starch hydrolysates, such as LYCASIN, acommercially available product manufactured by Roquette Freres ofFrance, and HYSTAR, a commercially available product manufactured byLonza, Inc., of Fairlawn, N.J., are also useful.

The sweetening agents used may be selected from. a wide range ofmaterials including water-soluble sweeteners, water-soluble artificialsweeteners, water-soluble sweeteners derived from naturally occurringwater-soluble sweeteners, dipeptide based sweeteners, and protein basedsweeteners, including mixtures thereof. Without being limited toparticular sweeteners, representative categories and examples include:

(a) water-soluble sweetening agents such asdihydrochalcones, monellin,steviosides, glycyrrhizin, dihydroflavenol, and sugar alcohols such assorbitol, mannitol, maltitol, and L-aminodicarboxylic acid aminoalkenoicacid ester amides, such as those disclosed in U.S. Pat. No. 4,619,834,which disclosure is incorporated herein by reference, and the like, andmixtures thereof;

(b) water-soluble artificial sweeteners such as soluble saccharin salts,i.e., sodium or calcium saccharin salts, cyclamate salts, the sodium,ammonium or calcium salt of3,4-dihydro-6-methyl-1,2,3-oxathiazine-4-one-2,2-dioxide, the potassiumsalt of 3,4-dihydro-6-methyl-1,2,3-oxathiazine-4-one-2,2-dioxide(Acesulfame-K), the free acid form of saccharin, and the like, andmixtures thereof;

(c) dipeptide based sweeteners, such as L-aspartic acid derivedsweeteners, such as L-aspartyl-L-phenylalanine methyl ester (Aspartame)and materials described in U.S. Pat. No. 3,492,131,L-alphaaspartyl-N-(2,2,4,4-tetramethyl-3-thietanyl)-D-alaninamidehydrate (Alitame), methyl esters of L-aspartyl-L-phenylglycerine andL-aspartyl-L-2,5-dihydrophenyl-glycine,L-aspartyl-2,5-dihydro-L-phenylalanine;L-aspartyl-L-(l-cyclohexen)-alanine, and the like, and mixtures thereof;

(d) water-soluble sweeteners derived from naturally occurringwater-soluble sweeteners, such as chlorinated derivatives of ordinarysugar (sucrose), e.g., chlorodeoxysugar derivatives such as derivativesof chlorodeoxysucrose or chlorodeoxygalactosucrose, known, for example,under the product designation of Sucralose; examples ofchlorodeoxysucrose and chlorodeoxygalactosucrose derivatives include butare not limited to: 1-chloro-1'-deoxysucrose;4-chloro-4-deoxy-alpha-D-galactopyranosyl-alpha-D-fructofuranoside, or4-chloro-4-deoxygalactosucrose;4-chloro-4-deoxy-alpha-D-galactopyranosyl-1-chloro-l-deoxy-beta-D-fructo-furanoside,or 4,1'-dichloro-4,1'-dideoxygalactosucrose;1',6'-dichloro1',6'-dideoxysucrose;4-chloro-4-deoxy-alpha-D-galactopyranosyl-1,6-dichloro-l,6-dideoxy-beta-D-fructofuranoside,or 4,1',6'-trichloro-4,1',6'-trideoxygalactosucrose;4,6-dichloro-4,6-dideoxy-alpha-D-galactopyranosyl-6-chloro-6-deoxy-beta-D-fructofuranoside,or 4,6,6'-trichloro-4,6,6'-trideoxygalactosucrose;6,1',6'-trichloro-6,1',6'-trideoxysucrose;4,6-dichloro-4,6-dideoxy-alpha-D-galacto-pyranosyl-1,6-dichloro-l,6-dideoxy-beta-D-fructofuranoside,or 4,6,1',6'-tetrachloro4,6,1',6'-tetradeoxygalacto-sucrose; and4,6,1',6'-tetradeoxy-sucrose, and mixtures thereof; and

(e) protein based sweeteners such as thaumaoccous danielli (Thaumatin Iand II).

The intense sweetening agents of the present invention may be used inmany distinct physical forms well known in the art to provide an initialburst of sweetness and/or a prolonged sensation of sweetness. Withoutbeing limited thereto, such physical forms include free forms, such asspray dried, powdered, and beaded forms, and encapsulated forms, andmixtures thereof.

In general, an effective amount of sweetener is utilized to provide thelevel of sweetness desired, and this amount will vary with the sweetenerselected. The amount of sweetener will normally be present in amountsfrom about 0.001% to about 3%, by weight of the gum composition,depending upon the sweetener used. The exact range of amounts for eachtype of sweetener is well known in the art and is not the subject of thepresent invention.

The flavoring agents which may be used include those flavors known tothe skilled artisan, such as natural and artificial flavors. Theseflavorings may be chosen from synthetic flavor oils and flavoringaromatics and/or oils, oleoresins and extracts derived from plants,leaves, flowers, fruits, and so forth, and combinations thereof.Nonlimiting representative flavor oils include spearmint oil, cinnamonoil, oil of wintergreen (methyl salicylate), peppermint oil, clove oil,bay oil, anise oil, eucalyptus oil, thyme oil, cedar leaf oil, oil ofnutmeg, allspice, oil of sage, mace, oil of bitter almonds, and cassiaoil. Also useful flavorings are artificial, natural and synthetic fruitflavors such as vanilla, and citrus oils including lemon, orange, lime,grapefruit, and fruit essences including apple, pear, peach, grape,strawberry, raspberry, cherry, plum, pineapple, apricot and so forth.These flavoring agents may be used in liquid or solid form and may beused individually or in admixture. Commonly used flavors include mintssuch as peppermint, menthol, artificial vanilla, cinnamon derivatives,and various fruit flavors, whether employed individually or inadmixture.

Other useful flavorings include aldehydes and esters such as cinnamylacetate, cinnamaldehyde, citral diethylacetal, dihydrocarvyl acetate,eugenyl formate, p-methylamisol, and so forth may be used. Generally anyflavoring or food additive such as those described in Chemicals Used inFood Processing, publication 1274, pages 63-258, by the National Academyof Sciences, may be used.

Further examples of aldehyde flavorings include but are not limited toacetaldehyde (apple), benzaldehyde (cherry, almond), anisic aldehyde(licorice, anise), cinnamic aldehyde (cinnamon), citral, i.e.,alpha-citral (lemon, lime), neral, i.e., beta-citral (lemon, lime),decanal (orange, lemon), ethyl vanillin (vanilla, cream), heliotrope,i.e., piperonal (vanilla, cream), vanillin (vanilla, cream), alpha-amylcinnamaldehyde (spicy fruity flavors), butyraldehyde (butter, cheese),valeraldehyde (butter, cheese), citronellal (modifies, many types),decanal (citrus fruits), aldehyde C-8 (citrus fruits), aldehyde C-9(citrus fruits), aldehyde C-12 (citrus fruits), 2-ethyl butyraldehyde(berry fruits), hexenal, i.e., trans-2 (berry fruits), tolyl aldehyde(cherry, almond), veratraldehyde (vanilla), 2,6-dimethyl-5-heptenal,i.e., melonal (melon), 2,6-dimethyloctanal (green fruit), and2-dodecenal (citrus, mandarin), cherry, grape, strawberry shortcake,mixtures thereof and the like.

The flavoring agent may be employed in either liquid form and/or driedform. When employed in the latter form, suitable drying means such asspray drying the oil may be used. Alternatively, the flavoring agent maybe absorbed onto water soluble materials, such as cellulose, starch,sugar, maltodextrin, gum arabic and so forth or may be encapsulated. Theactual techniques for preparing such dried forms are well known and donot constitute a part of this invention.

The flavoring agents of the present invention may be used in manydistinct physical forms well known in the art to provide an initialburst of flavor and/or a prolonged sensation of flavor. Without beinglimited thereto, such physical forms include free forms, such as spraydried, powdered, and beaded forms, and encapsulated forms, and mixturesthereof.

The amount of flavoring agent employed herein is normally a matter ofpreference subject to such factors as the type of final chewing gumcomposition, the individual flavor, the gum base employed, and thestrength of flavor desired. Thus, the amount of flavoring may be variedin order to obtain the result desired in the final product and suchvariations are within the capabilities of those skilled in the artwithout the need for undue experimentation. In gum compositions, theflavoring agent is generally present in amounts from about 0.02% toabout 5%, and preferably from about 0.1% to about 2%, and morepreferably, from about 0.8% to about 1.8%, by weight of the chewing gumcomposition.

The coloring agents useful in the present invention are used in amountseffective to produce the desired color. These coloring agents includepigments which may be incorporated in amounts up to about 6%, by weightof the gum composition. A preferred pigment, titanium dioxide, may beincorporated in amounts up to about 2%, and preferably less than about1%, by weight of the gum composition. The colorants may also includenatural food colors and dyes suitable for food, drug and cosmeticapplications. These colorants are known as F.D.& C. dyes and lakes. Thematerials acceptable for the foregoing uses are preferablywater-soluble. Illustrative nonlimiting examples include the indigoiddye known as F.D.& C. Blue No.2, which is the disodium salt of5,5-indigotindisulfonic acid. Similarly, the dye known as F.D.& C. GreenNo.1 comprises a triphenylmethane dye and is the monosodium salt of4-[4-(N-ethyl-p-sulfoniumbenzylamino) diphenylmethylene]-[1-(N-ethyl-N-p-sulfoniumbenzyl)-delta-2,5-cyclohexadieneimine]. A full recitationof all F.D.& C. colorants and their corresponding chemical structuresmay be found in the Kirk-Othmer Encyclopedia of Chemical Technology, 3rdEdition, in volume 5 at pages 857-884, which text is incorporated hereinby reference.

Suitable oils and fats usable in gum compositions include partiallyhydrogenated vegetable or animal fats, such as coconut oil, palm kerneloil, beef tallow, lard, and the like. These ingredients when used aregenerally present in amounts up to about 7%, and preferably up to about3.5%, by weight of the gum composition.

In a preferred embodiment, the invention is directed at a center-filledchewing gum composition having an outer shell enclosing a cavity and aliquid center within the cavity, wherein the outer shell comprises achewing gum composition comprising (A) a gum base present in an amountfrom about 40% to about 85%, by weight of the chewing gum composition,which comprises (a) an elastomer present in an amount from about 0.5% toabout 20%, by weight of the gum base, (b) a medium molecular weightpolyvinyl acetate polymer having a molecular weight from about 35,000 toabout 55,000 present in an amount from about 10% to about 25%, by weightof the gum base, (c) an acetylated monoglyceride present in an amountfrom about 4.5% to about 10%, by weight of the gum base, (d) a waxhaving a melting point below about 60° C. present in an amount fromabout 6% to about 10%, by weight of the gum base, (e) an elastomersolvent present in an amount from about 2% to about 11%, by weight ofthe gum base, (f) a plasticizer in an amount from about 5% to about 14%,by weight of the gum base, and (g) a filler in an amount from about 15%to about 40%, by weight of the gum base, and (B) a bulking agent presentin an amount up to about 60%, by weight of the chewing gum composition

The present invention also includes a method for preparing the improvedchewing gum compositions, including both chewing gum and bubble gumformulations. The chewing gum compositions may be prepared usingstandard techniques and equipment known to those skilled in the art. Theapparatus useful in accordance with the present invention comprisesmixing and heating apparatus well known in the chewing gum manufacturingarts, and therefore the selection of the specific apparatus will beapparent to the artisan

In such a method, a chewing gum composition is made by admixing theinventive gum base with the other ingredients of the final desiredchewing gum composition. Other ingredients will usually be incorporatedinto the composition as dictated by the nature of the desiredcomposition as well known by those having ordinary skill in the art. Theultimate chewing gum compositions are readily prepared using methodsgenerally known in the food technology and chewing gum arts.

For example, the inventive gum base is heated to a temperaturesufficiently high to soften the base without adversely effecting thephysical and chemical make up of the base. The optimal temperaturesutilized may vary depending upon the composition of the gum base used,but such temperatures are readily determined by those skilled in the artwithout undue experimentation.

The gum base is conventionally melted at temperatures that range fromabout 60° C. to about 120° C. for a period of time sufficient to renderthe base molten. For example, the gum base may be heated under theseconditions for a period of about thirty minutes just prior to beingadmixed incrementally with the remaining ingredients of the gumcomposition such as the plasticizer, the softener, the bulking agent,the sweetener, and/or fillers, coloring agents and flavoring agents toplasticize the blend as well as to modulate the hardness,viscoelasticity and formability of the base. Mixing is continued until auniform mixture of gum composition is obtained Thereafter the gumcomposition mixture may be formed into desirable chewing gum shapes.

In one embodiment, the invention is directed at a method for preparingan outer shell in a center-filled chewing gum composition, wherein theouter shell is comprised of a gum base having an enhanced hydrophilicnature, which comprises the steps of (I) providing the ingredients ofthe gum base having an enhanced hydrophilic nature, and (2) admixing theingredients in step (1) to form a uniform mixture.

In another embodiment, the invention is directed at a method forpreparing an outer shell in a center-filled chewing gum composition,wherein the outer shell is comprised of a chewing gum composition, whichcomprises the steps of (1) providing the following ingredients of thechewing gum composition (A) a gum base having an enhanced hydrophilicnature present in an amount from about 40% to about 85%, by weight ofthe chewing gum composition, and (B) a bulking agent present in anamount up to about 60%, by weight of the chewing gum composition, (2)admixing the ingredients in step (A) to form a uniform mixture, and (3)admixing the ingredients in step (B) to the mixture of step (2) to forma uniform mixture.

In a preferred embodiment, the invention is directed to a method forpreparing an outer shell in a center-filled chewing gum composition,wherein the outer shell is comprised of a gum base, which comprises thesteps of (1) providing the following ingredients in percentages byweight of the gum base (a) an elastomer present in an amount from about0.5% to about 20%, (b) a medium molecular weight polyvinyl acetatepolymer having a molecular weight from about 35,000 to about 55,000present in an amount from about 10% to about 25%, (c) an acetylatedmonoglyceride present in an amount from about 4.5% to about 10%, (d) awax having a melting point below about 60° C. present in an amount fromabout 6% to about 10%, and (e) a component selected from the groupconsisting of elastomer solvents, emulsifiers, plasticizers, fillers,and mixtures thereof, present in an amount to bring the total amount ofgum base to 100%, and (2) admixing the ingredients in step (1) to form auniform mixture.

In another preferred embodiment, the invention is directed to a methodfor preparing an outer shell in a center-filled chewing gum composition,wherein the outer shell is comprised of a chewing gum composition, whichcomprises the steps of (1) providing the following ingredients of thechewing gum composition (A) a gum base present in an amount from about40% to about 85%, by weight of the chewing gum composition, whichcomprises (a) an elastomer present in an amount from about 0.5% to about20%, by weight of the gum base, (b) a medium molecular weight polyvinylacetate polymer having a molecular weight from about 35,000 to about55,000 present in an amount from about 10% to about 25%, by weight ofthe gum base, (c) an acetylated monoglyceride present in an amount fromabout 4.5% to about 10%, by weight of the gum base, (d) a wax having amelting point below about 60° C. present in an amount from about 6 toabout 10%, by weight of the gum base, and (e) a material selected fromthe group consisting of elastomer solvents, emulsifiers, plasticizers,fillers, and mixtures thereof, present in an amount to bring the totalamount of gum base to 100%, by weight of the gum base, and (B) a bulkingagent present in an amount up to about 60%, by weight of the chewing gumcomposition, (2) admixing the ingredients in step (A) to form a uniformmixture, and (3) admixing the ingredients in step (B) to the mixture ofstep (2) to form a uniform mixture.

In accord with the present invention, the gum base and chewing gumcompositions incorporating the inventive gum base may be used as theouter shell of a center-filled chewing gum enclosing a liquid center.The liquid center employed in this invention may be any liquid centerwell known in the art, including sugar and sugarless liquid centers.These liquid centers include, without limitation, substantially aqueouscenters, aqueous centers containing additives such as thickeners,emulsifiers, humectants, binders, gums, and the like, and mixturesthereof to prevent migration of the liquid center, suspensions, andsemi-liquid centers, wherein the viscosity of the liquid center canrange from a gel-like consistency or pasty quality, to a relativelythixotropic, sticky liquid quality.

The liquid centers may contain those traditional ingredients well knownin the chewing gum and confectionery arts such as flavoring agents,sweetening agents, and the like, and mixtures thereof. In addition toconfectionery additives, the liquid centers may also containpharmaceutical additives such as medicaments, breath fresheners,vitamins, fruit juices, and the like, and mixtures thereof. Theconfectionery and pharmaceutical agents may be used in many distinctphysical forms well known in the art to provide an initial burst ofsweetness and flavor and/or therapeutic activity or a prolongedsensation of sweetness and flavor and/or therapeutic activity. Withoutbeing limited thereto, such physical forms include free forms, such asspray dried, powdered, and beaded forms, and encapsulated forms, andmixtures thereof. Illustrative, but not limiting, examples of liquidcenters suitable for use in the present invention include those centersdisclosed in U.S. Pat. Nos. 3,894,154, 4,156,740, 4,157,402, 4,316,915,and 4,466,983, which disclosures are incorporated herein by reference.

Because of the increased hydrophobic properties of the outer shell inthe present invention which retard migration of the liquid center, asignificantly higher ratio of liquid center to solid outer shell may beincorporated into the center-filled chewing gums of this invention. Thesmaller amount of solid outer shell in the center-filled chewing gumproduct enables the preparation of reduced-calorie chewing gums. Ingeneral, the liquid center will be present in the center-filled chewinggum in an amount from about 15% to about 50%, and preferably from about20% to about 35%, by weight of the final chewing gum product.

The present invention extends to methods of making the improvedcenter-filled chewing gum compositions. The improved compositions may beprepared using standard techniques and equipment known to those skilledin the art. The apparatus useful in accordance with the presentinvention comprises mixing and heating apparatus well known in thechewing gum manufacturing arts, and therefore the selection of thespecific apparatus will be apparent to the artisan Such methods andapparatus are disclosed, for example, in U.S. Pat. Nos. 3,806,290 and3,857,963, which disclosures are incorporated herein by reference

Typically, the gum base of this invention, or a chewing gum compositionincorporating the gum base of this invention, is fed into a gum extruderand extruded through an orifice as a hollow-centered rope of chewinggum. A liquid center formulation is fed, under pressure, through aninner conduit to the hollow-center of the rope downstream of the orificeand the center-filled rope of chewing gum is passed into a sizing unitwhere rollers decrease the cross sectional dimension of the rope gum andform individual gum units.

In a preferred embodiment, the invention is directed to a method forpreparing a center-filled chewing gum composition which comprisesenclosing a cavity containing a liquid center with an outer shell,wherein the outer shell comprises a gum base comprising in percentagesby weight (a) an elastomer present in an amount from about 0.5% to about20%, (b) a medium molecular weight polyvinyl acetate polymer having amolecular weight from about 35,000 to about 55,000 present in an amountfrom about 10% to about 25%, (c) an acetylated monoglyceride present inan amount from about 4.5% to about 10%, (d) a wax having a melting pointbelow about 60° C. present in an amount from about 6 to about 10%, and(e) a component selected from the group consisting of elastomersolvents, emulsifiers, plasticizers, fillers, and mixtures thereof,present in an amount to bring the total amount of gum base to 100%.

In another preferred embodiment, the invention is directed to a methodfor preparing a center-filled chewing gum composition which comprisesenclosing a cavity containing a liquid center with an outer shell,wherein the outer shell comprises a chewing gum composition comprising(A) a gum base present in an amount from about 40% to about 85%, byweight of the chewing gum composition, which comprises (a) an elastomerpresent in an amount from about 0.5% to about 20%, by weight of the gumbase, (b) a medium molecular weight polyvinyl acetate polymer having amolecular weight from about 35,000 to about 55,000 present in an amountfrom about 10% to about 25%, by weight of the gum base, (c) anacetylated monoglyceride present in an amount from about 4.5% to about10%, by weight of the gum base, (d) a wax having a melting point belowabout 60° C. present in an amount from about 6 to about 10%, by weightof the gum base, and (e) a material selected from the group consistingof elastomer solvents, emulsifiers, plasticizers, fillers, and mixturesthereof, present in an amount to bring the total amount of gum base to100%, by weight of the gum base, and (B) a bulking agent present in anamount up to about 60%, by weight of the chewing gum composition.

The present invention is further illustrated by the following exampleswhich are not intended to limit the effective scope of the claims. Allparts and percentages in the examples and throughout the specificationand claims are by weight of the final composition unless otherwisespecified.

EXAMPLES 1-7 Noninventive Runs 1-2 Inventive Runs 3-7

These examples demonstrate a comparison between conventionalcenter-filled chewing gum compositions and center-filled chewing gumcompositions prepared according to the present invention having improvedstability during storage. The gum base composition of examples 1-2(controls) and examples 3-7 (test samples) are set out in Table 1.

                  TABLE 1                                                         ______________________________________                                        GUM BASE COMPOSITION (Percent By Weight)                                      Example         1-2       3-7                                                 Ingredient      (Controls)                                                                              (Test Samples)                                      ______________________________________                                        Elastomer       12        10                                                  Polyvinyl acetate                                                             low molecular weight                                                                          20        12                                                  medium molecular weight                                                                       --        12                                                  Acetylated monoglyceride                                                                      --        6.5                                                 Wax             19        9                                                   Glyceryl ester of partially                                                                   26        8                                                   hydrogenated wood resin                                                       Partially hydrogenated                                                                         5        9                                                   vegetable oil/animal fat                                                      Emulsifier       7        8                                                   Filler          11        25.5                                                ______________________________________                                    

The chewing gum compositions of examples 1-2 (controls) and examples 3-7(test samples) are set out in Table 2.

                  TABLE 2                                                         ______________________________________                                        CHEWING GUM COMPOSITION (Percentages By Weight)                               Example   1       2      3    4    5    6    7                                Ingredient                                                                              (Controls) (Test Samples)                                           ______________________________________                                        Gum Base  28.0    28.0   65.0 65.0 65.0 65.0 65.0                             Carbohydrates                                                                 Sugarless 52.3           27.45                                                                              27.45                                           Sugar             52.3                  27.45                                 Sugarless                                                                     with Xylitol                       27.45                                      Fructose                                     27.45                            Softening 18.0    18.0   5.1  5.1  5.1  5.1  5.1                              agent                                                                         Flavoring                                                                     agent                                                                         Peppermint                                                                              1.35    1.35   2.0       2.0  2.0  2.0                              Trident                       2.0                                             Sweetening                                                                              0.35    0.35   0.45 0.45 0.45 0.45 0.45                             agent                                                                         ______________________________________                                    

Center-filled chewing gum compositions were prepared incorporating theliquid centers set out in Table 3 and containing the gum basecompositions set out in Table 1 and the chewing gum compositions set outin Table 2.

                  TABLE 3                                                         ______________________________________                                        LIQUID CENTER COMPOSITION (Percentages By Weight)                             Example  Ingredients                                                          ______________________________________                                        1        69%     Sugarless Humectants and Thickeners                          (Control)                                                                              1%      Flavoring Agent                                                       30%     Water                                                        2        59%     Sugar Humectants and Thickeners                              (Control)                                                                              1%      Flavoring Agent                                                       40%     Water                                                        3        100%    Lycasin                                                      4        100%    Glyderin                                                     5        100%    Water                                                        6        69%     Sugarless Humectants and Thickeners                                   1%      Flavoring Agent                                                       30%     Water                                                        7        97%     Glycerin                                                              3%      Flavoring Agent                                              ______________________________________                                    

The weight ratio of liquid center to outer shell in the center-filledchewing gum compositions of example 1-2 (controls) was about 20% and theweight ratio of liquid center to outer shell in the center-filledchewing gum compositions of examples 3-7 (test samples) was about 30%.The center-filled chewing gum compositions of examples 1-7 were storedat 37° C. and observed periodically for stability.

At the end of one week, the centers in all the center-filled chewing gumcompositions were stable. At the end of two weeks, the centers in thechewing gum compositions were satisfactory, however, the centers in thechewing gums of examples 1 and 2 (controls) and in example 5 (watercenter-test sample) were becoming thick. At the end of four weeks, thecenters in the chewing gums of examples 1 and 2 (controls) had driedout, the center in example 5 (water center-test sample) was thick, andthe centers in the chewing gum compositions of examples 4, 6 and 7 (testsamples) were acceptable. At the end of seven weeks, the centers in thechewing gum compositions of examples 3-7 (test samples) showed nofurther change. At the end of eight weeks, the centers in the chewinggum compositions of examples 3-7 (test samples) still had an acceptablesquirt center, even the center in example 5 (water center-test sample)which had become a thick tacky mass. At the end of twelve weeks, thecenters in the chewing gum compositions of examples 3-7 (test samples)still had an acceptable squirt center, including the center in thechewing gum of example 5 (water center-test sample).

Accordingly, the center-filled chewing gum compositions of examples 3-7,which contained the inventive gum base composition, were much morestable during storage than the control compositions of examples 1-2.

The amount of moisture absorbed by the chewing gum compositions ofexamples 1-2 (control) and 3-7 (test samples) was measured over a periodof six weeks at a temperature of 27° C. and a relative humidity (RH) of80%. The amount of moisture absorbed by each gum composition, inpercentage moisture absorbed by weight versus weeks of storage, is setout in FIG. 1. FIG. 1 shows that the chewing gum compositions ofexamples 3-7, which contained the inventive gum base, absorbedsignificantly less moisture than the conventional chewing gumcompositions of examples 1-2.

EXAMPLES 8-11

These examples demonstrate a comparison between center-filled chewinggum compositions containing different levels of the gum base of thepresent invention. The composition of the gum base is that set out abovefor examples 3-7. The chewing gum compositions of examples 8-11 are setout in Table 4.

                  TABLE 4                                                         ______________________________________                                        CHEWING GUM COMPOSITION (Percentages By Weight)                                            EXAMPLE                                                          Ingredient     8      9         10   11                                       ______________________________________                                        Gum Base       23     26        65   85                                       Carbohydrates  72.55  69.55     27.45                                                                              7.45                                     Softening agent                                                                              19     18        5.1  5.1                                      Flavoring agent                                                                              2      2         2    2                                        Sweetening agent                                                                             0.45   0.45      0.45 0.45                                     ______________________________________                                    

Center-filled chewing gum compositions were prepared from each chewinggum composition set out in Table 4 (examples 8-11) incorporating each ofthe liquid centers (examples A-C) set out in Table 5.

                  TABLE 5                                                         ______________________________________                                        LIQUID CENTER COMPOSITION (Percentages By Weight)                             Example  Ingredients                                                          ______________________________________                                        A        69%     Sugarless humectants and thickeners                                   1%      Flavoring agent                                                       30%     Water                                                        B        100%    Sorbitol Solution                                            C        100%    Water                                                        ______________________________________                                    

The weight ratio of liquid center to outer shell in the center-filledchewing gum compositions of examples 8-11 was about 30%. Thecenter-filled chewing gum compositions were stored at 37° C. andobserved periodically for stability.

At the end of one hour, the center in the gum composition of example 8C(water center-23% gum base) started to migrate. At the end of two hours,the center in the gum composition of example 9C (water center-26% gumbase) also started to migrate. At the end of four hours, the center ofexample 8C (water center-23% gum base) disappeared, the center ofexample 9C (water center-26% gum base) was almost gone, and the centerof example 8B (sorbitol solution center-23% gum base) started tomigrate.

At the end of five days, the center of example 9C (water center-26% gumbase) had migrated, the centers of examples 9B and l0B (sorbitolsolution center-26% gum base and 65% gum base) had started to migrate,the center of example l0C (water center-65% gum base) had started tomigrate, and the centers of examples 11B and 11C (sorbitol solutioncenter and water center, respectively-85% gum base) were stillacceptable. The centers of examples 8A, 9A, 10A and 11A (69% sugarlesshumectants and thickeners, 1% flavoring agent and 30% water center) hadstarted to migrate with the center of example 8A (23% gum base) showinggreatest migration and the center of example 11A (85% gum base) showingleast migration.

At the end of eleven days, only the centers of examples 8A, 9A, 10A and11A (69% sugarless humectants and thickeners, 1% flavoring agent and 30%water center) were acceptable with the center of example 8A (23% gumbase) being very tacky and the center of example 11A (85% gum base)showing only slight migration.

In the remaining samples, an aliquot of the center of the sample wastaken and the percent solids of the center was measured using a Bausch &Lomb refractometer. The centers were prepared with an initial percentsolids of 72%. As the centers migrate, the percent solids increase.

At the end of one month, the center of example 8A (69% sugarlesshumectants and thickeners, 1% flavoring agent and 30% water center-23%gum base) was very thick and had a percent solids of 82%. The center ofexample 11A (69% sugarless humectants and thickeners, 1% flavoring agentand 30% water center-85% gum base) was still fluid and had a percentsolids of 72%.

At the end of two months, the center of example 8A (69% sugarlesshumectants and thickeners, 1% flavoring agent and 30% water center-23%gum base) had migrated significantly and an aliquot could not be takenfor analysis of percent solids. The center of example IIA (69% sugarlesshumectants and thickeners, 1% flavoring agent and 30% water center-85%gum base) was still fluid and had a percent solids of 72%.

At the end of three months, the centers of examples 10A and 11A (69%sugarless humectants and thickeners, 1% flavoring agent and 30% watercenter-65% gum base and 85% gum base, respectively) were still fluid andeach had a percent solids of 74%.

Accordingly, the center-filled chewing gum compositions of examples 10and 11, which contained higher amounts of the inventive gum basecomposition (65% and 85%, respectively), were much more stable duringstorage than the gum compositions of examples 8 and 9 which containedsmaller amounts of the gum base (23% and 26%, respectively).

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention and all suchmodifications are intended to be included within the scope of thefollowing claims

We claim:
 1. A center-filled chewing gum composition having an outershell enclosing a cavity and a liquid center within the cavity, whereinthe outer shell comprises a gum base comprising in percentages by weightof the gum base:(a) an elastomer present in an amount from about 0.5% toabout 20%; (b) a medium molecular weight polyvinyl acetate polymerhaving a molecular weight from about 35,000 to about 55,000 present inan amount from about 10% to about 25%; (c) an acetylated monoglyceridepresent in an amount from about 4.5% to about 10%; (d) a wax having amelting point below about 60° C. present in an amount from about 6% toabout 10%; and (e) a component selected from the group consisting ofelastomer solvents, emulsifiers, plasticizers, fillers, and mixturesthereof, present in an amount to bring the total amount of gum base to100%.
 2. The center-filled chewing gum composition according to claim 1,wherein the elastomer is selected from the group consisting of naturalgums, synthetic gums, and mixtures thereof.
 3. The center-filled chewinggum composition according to claim 1, wherein the elastomer is presentin an amount from about 2.5% to about 15%, by weight of the gum base. 4.The center-filled chewing gum composition according to claim 1, whereinthe polyvinyl acetate polymer is present in amount from about 12% toabout 17%, by weight of the gum base.
 5. The center-filled chewing gumcomposition according to claim 1, further comprising a low molecularweight polyvinyl acetate polymer having a molecular weight from about12,000 to about 16,000 present in an amount up to about 17%, by weightof the gum base.
 6. The center-filled chewing gum composition accordingto claim 5, wherein the low molecular weight polyvinyl acetate polymeris present in an amount from about 12% to about 17%, by weight of thegum base.
 7. The center-filled chewing gum composition according toclaim 5, wherein the mole ratio of low molecular weight polyvinylacetate polymer to medium molecular weight polyvinyl acetate polymer isfrom about 1:0.5 to about 1:1.5, respectively.
 8. The center-filledchewing gum composition according to claim 1, wherein the acetylatedmonoglyceride has a saponification value above about
 400. 9. Thecenter-filled chewing gum composition according to claim 1, wherein theacetylated monoglyceride is present in an amount from about 5% to about9%, by weight of the gum base.
 10. The center-filled chewing gumcomposition according to claim 1, wherein the wax is a paraffin waxhaving a melting point between about 45° C. and about 55° C.
 11. Thecenter-filled chewing gum composition according to claim 1, wherein thewax is present in an amount from about 7% to about 9.5%, by weight ofthe gum base.
 12. The center-filled chewing gum composition according toclaim 1, wherein the elastomer solvent is present and is selected fromthe group consisting of the pentaerythritol ester of partiallyhydrogenated wood and gum rosin, the pentaerythritol ester of wood andgum rosin, the glycerol ester of wood rosin, the glycerol ester ofpartially dimerized wood and gum rosin, the glycerol ester ofpolymerized wood and gum rosin, the glycerol ester of tall oil rosin,the glycerol ester of wood and gum rosin and the partially hydrogenatedwood and gum rosin and the partially hydrogenated methyl ester of woodand rosin, and mixtures thereof.
 13. The center-filled chewing gumcomposition according to claim 1, wherein the elastomer solvent ispresent in an amount from about 2% to about 12%, by weight of the gumbase.
 14. The center-filled chewing gum composition according to claim1, wherein the plasticizer is present and is a hydrogenated vegetableoil selected from the group consisting of soybean oil, cotton seed oil,and mixtures thereof.
 15. The center-filled chewing gum compositionaccording to claim 1, wherein the plasticizer is present in an amountfrom about 5% to about 13%, by weight of the gum base.
 16. Thecenter-filled chewing gum composition according to claim 1, wherein thefiller is present in an amount from about 15% to about 40%, by weight ofthe gum base.
 17. The center-filled chewing gum composition according toclaim 1, wherein the liquid center is present in an amount from about15% to about 50%, by weight of the gum composition.
 18. A center-filledchewing gum composition having an outer shell enclosing a cavity and aliquid center within the cavity, wherein the outer shell comprises a gumbase comprising in percentages by weight of the gum base:(a) anelastomer present in an amount from about 0.5% to about 20%; (b) amedium molecular weight polyvinyl acetate polymer having a molecularweight from about 35,000 to about 55,000 present in an amount from about10% to about 25%; (c) an acetylated monoglyceride present in an amountfrom about 4.5% to about 10%; (d) a wax having a melting point belowabout 60° C. present in an amount from about 6% to about 10%; (e) anelastomer solvent present in an amount from about 2% to about 11%; (f) aplasticizer in an amount from about 5% to about 14%; and (g) a filler inan amount from about 15% to about 40%.
 19. A center-filled chewing gumcomposition having an outer shell enclosing a cavity and a liquid centerwithin the cavity, wherein the outer shell comprises a chewing gumcomposition comprising:(A) a gum base present in an amount from about40% to about 85%, by weight of the chewing gum composition, whichcomprises: (a) an elastomer present in an amount from about 0.5% toabout 20%, by weight of the gum base; (b) a medium molecular weightpolyvinyl acetate polymer having a molecular weight from about 35,000 toabout 55,000 present in an amount from about 10% to about 25%, by weightof the gum base; (c) an acetylated monoglyceride present in an amountfrom about 4.5% to about 10%, by weight of the gum base; (d) a waxhaving a melting point below about 60° C. present in an amount fromabout 6% to about 10%, by weight of the gum base; and (e) a materialselected from the group consisting of elastomer solvents, emulsifiers,plasticizers, fillers, and mixtures thereof, present in an amount tobring the total amount of gum base to 100%, by weight of the gum base;and (B) a bulking agent present in an amount up to about 60%, by weightof the chewing gum composition.
 20. The center-filled chewing gumcomposition according to claim 19, wherein the elastomer is selectedfrom the group consisting of natural gums, synthetic gums, and mixturesthereof.
 21. The center-filled chewing gum composition according toclaim 19, wherein the elastomer is present in an amount from about 2.5%to about 15%, by weight of the gum base.
 22. The center-filled chewinggum composition according to claim 19, wherein the polyvinyl acetatepolymer is present in amount from about 12% to about 17%, by weight ofthe gum base.
 23. The center-filled chewing gum composition according toclaim 19, further comprising a low molecular weight polyvinyl acetatepolymer having a molecular weight from about 12,000 to about 16,000present in an amount up to about 17%, by weight of the gum base.
 24. Thecenter-filled chewing gum composition according to claim 23, wherein thelow molecular weight polyvinyl acetate polymer is present in an amountfrom about 12% to about 17%, by weight of the gum base.
 25. Thecenter-filled chewing gum composition according to claim 23, wherein themole ratio of low molecular weight polyvinyl acetate polymer to mediummolecular weight polyvinyl acetate polymer is from about 1:0.5 to about1:1.5, respectively.
 26. The center-filled chewing gum compositionaccording to claim 19, wherein the acetylated monoglyceride has asaponification value above about
 400. 27. The center-filled chewing gumcomposition according to claim 19, wherein the acetylated monoglycerideis present in an amount from about 5% to about 9%, by weight of the gumbase.
 28. The center-filled chewing gum composition according to claim19, wherein the wax is a paraffin wax having a melting point betweenabout 45° C. and about 55° C.
 29. The center-filled chewing gumcomposition according to claim 19, wherein the wax is present in anamount from about 7% to about 9.5%, by weight of the gum base.
 30. Thecenter-filled chewing gum composition according to claim 19, wherein theelastomer solvent is present and is selected from the group consistingof the pentaerythritol ester of partially hydrogenated wood and gumrosin, the pentaerythritol ester of wood and gum rosin, the glycerolester of wood rosin, the glycerol ester of partially dimerized wood andgum rosin, the glycerol ester of polymerized wood and gum rosin, theglycerol ester of tall oil rosin, the glycerol ester of wood and gumrosin and the partially hydrogenated wood and gum rosin and thepartially hydrogenated methyl ester of wood and rosin, and mixturesthereof.
 31. The center-filled chewing gum composition according toclaim 19, wherein the elastomer solvent is present in an amount fromabout 2% to about 12%, by weight of the gum base.
 32. The center-filledchewing gum composition according to claim 19, wherein the plasticizeris present and is a hydrogenated vegetable oil selected from the groupconsisting of soybean oil, cotton seed oil, and mixtures thereof
 33. Thecenter-filled chewing gum composition according to claim 19, wherein theplasticizer is present in an amount from about 5% to about 13%, byweight of the gum base.
 34. The center-filled chewing gum compositionaccording to claim 19, wherein the filler is present in an amount fromabout 15% to about 40%, by weight of the gum base.
 35. The center-filledchewing gum composition according to claim 19, wherein the liquid centeris present in an amount from about 15% to about 50%, by weight of thegum composition.
 36. The center-filled chewing gum composition accordingto claim 19, wherein the bulking agent is present in an amount fromabout 15% to about 60%, by weight of the gum composition.
 37. Acenter-filled chewing gum composition having an outer shell enclosing acavity and a liquid center within the cavity, wherein the outer shellcomprises a chewing gum composition comprising:(A) a gum base present inan amount from about 40% to about 85%, by weight of the chewing gumcomposition, which comprises:(a) an elastomer present in an amount fromabout 0.5% to about 20%, by weight of the gum base; (b) a mediummolecular weight polyvinyl acetate polymer having a molecular weightfrom about 35,000 to about 55,000 present in an amount from about 10% toabout 25%, by weight of the gum base; (c) an acetylated monoglyceridepresent in an amount from about 4.5% to about 10%, by weight of the gumbase; (d) a wax having a melting point below about 60° C. present in anamount from about 6% to about by weight of the gum base; (e) anelastomer solvent present in an amount from about 2% to about 11%, byweight of the gum base; (f) a plasticizer in an amount from about toabout 14%, by weight of the gum base; and (g) a filler in an amount fromabout 15% to about 40%, by weight of the gum base; and (B) a bulkingagent present in an amount up to about 60%, by weight of the chewing gumcomposition.
 38. A method for preparing an outer shell in acenter-filled chewing gum composition, wherein the outer shell iscomprised of a gum base, which comprises the steps of:(1) providing thefollowing ingredients in percentages by weight of the gum base:(a) anelastomer present in an amount from about 0.5% to about 20%; (b) amedium molecular weight polyvinyl acetate polymer having a molecularweight from about 35,000 to about 55,000 present in an amount from about10% to about 25%; (c) an acetylated monoglyceride present in an amountfrom about 4.5% to about 10%; (d) a wax having a melting point belowabout 60° C. present in an amount from about 6% to about 10%; and (e) acomponent selected from the group consisting of elastomer solvents,emulsifiers, plasticizers, fillers, and mixtures thereof, present in anamount to bring the total amount of gum base to 100%; and (2) admixingthe ingredients in step (1) to form a uniform mixture.
 39. A method forpreparing an outer shell in a center-filled chewing gum composition,wherein the outer shell is comprised of a chewing gum composition, whichcomprises the steps of:(1) providing the following ingredients of thechewing gum composition:(A) a gum base present in an amount from about40% to about 85%, by weight of the chewing gum composition, whichcomprises(a) an elastomer present in an amount from about 0.5% to about20%, by weight of the gum base; (b) a medium molecular weight polyvinylacetate polymer having a molecular weight from about 35,000 to about55,000 present in an amount from about 10% to about 25%, by weight ofthe gum base; (c) an acetylated monoglyceride present in an amount fromabout 4 5% to about 10%, by weight of the gum base; (d) a wax having amelting point below about 60° C. present in an amount from about 6% toabout 10%, by weight of the gum base; and (e) a material selected fromthe group consisting of elastomer solvents, emulsifiers, plasticizers,fillers, and mixtures thereof, present in an amount to bring the totalamount of gum base to 100%, by weight of the gum base; and (B) a bulkingagent present in an amount up to about 60%, by weight of the chewing gumcomposition; (2) admixing the ingredients in step (A) to form a uniformmixture; and (3) admixing the ingredients in step (B) to the mixture ofstep (2) to form a uniform mixture.
 40. A method for preparing acenter-filled chewing gum composition which comprises enclosing a cavitycontaining a liquid center with an outer shell, wherein the outer shellcomprises a gum base comprising in percentages by weight of the gumbase:(a) an elastomer present in an amount from about 0.5% to about 20%;(b) a medium molecular weight polyvinyl acetate polymer having amolecular weight from about 35,000 to about 55,000 present in an amountfrom about 10% to about 25%; (c) an acetylated monoglyceride present inan amount from about 4.5% to about 10%; (d) a wax having a melting pointbelow about 60° C. present in an amount from about 6% to about 10%; and(e) a component selected from the group consisting of elastomersolvents, emulsifiers, plasticizers, fillers, and mixtures thereof,present in an amount to bring the total amount of gum base to 100%. 41.A method for preparing a center-filled chewing gum composition whichcomprises enclosing a cavity containing a liquid center with an outershell, wherein the outer shell comprises a chewing gum compositioncomprising:(A) a gum base present in an amount from about 40% to about85%, by weight of the chewing gum composition, which comprises:(a) anelastomer present in an amount from about 0.5% to about 20%, by weightof the gum base; (b) a medium molecular weight polyvinyl acetate polymerhaving a molecular weight from about 35,000 to about 55,000 present inan amount from about 10% to about 25%, by weight of the gum base; (c) anacetylated monoglyceride present in an amount from about 4.5% to about10%, by weight of the gum base; (d) a wax having a melting point belowabout 60° C. present in an amount from about 6% to about 10%, by weightof the gum base; and (e) a material selected from the group consistingof elastomer solvents, emulsifiers, plasticizers, fillers, and mixturesthereof, present in an amount to bring the total amount of gum base to100%, by weight of the gum base; and (B) a bulking agent present in anamount up to about 60%, by weight of the chewing gum composition.
 42. Acenter-filled chewing gum composition having an outer shell enclosing acavity and a liquid center within the cavity, wherein the outer shellcomprises a gum base having an enhanced hydrophilic nature.
 43. Thecenter-filled chewing gum composition according to claim 42, wherein theliquid center is present in an amount from about 15% to about 50%, byweight of the gum composition.
 44. A center-filled chewing gumcomposition having an outer shell enclosing a cavity and a liquid centerwithin the cavity, wherein the outer shell comprises a chewing gumcomposition comprising:(A) a gum base having an enhanced hydrophilicnature present in an amount from about 40% to about 85%, by weight ofthe chewing gum composition; and (B) a bulking agent present in anamount up to about 60%, by weight of the chewing gum composition. 45.The center-filled chewing gum composition according to claim 44, whereinthe liquid center is present in an amount from about 15% to about 50%,by weight of the gum composition.
 46. The center-filled chewing gumcomposition according to claim 44, wherein the bulking agent is presentin an amount from about 15% to about 60%, by weight of the gumcomposition.
 47. A method for preparing an outer shell in acenter-filled chewing gum composition, wherein the outer shell iscomprised of a gum base having an enhanced hydrophilic nature, whichcomprises the steps of:(1) providing the ingredients of the gum basehaving an enhanced hydrophilic nature, and (2) admixing the ingredientsin step (1) to form a uniform mixture.
 48. A method for preparing anouter shell in a center-filled chewing gum composition, wherein theouter shell is comprised of a chewing gum composition, which comprisesthe steps of:(1) providing the following ingredients of the chewing gumcomposition:(A) a gum base having an enhanced hydrophilic nature presentin an amount from about 40% to about 85%, by weight of the chewing gumcomposition; and (B) a bulking agent present in an amount up to about60%, by weight of the chewing gum composition; (2) admixing theingredients in step (A) to form a uniform mixture; and (3) admixing theingredients in step (B) to the mixture of step (2) to form a uniformmixture.
 49. A method for preparing a center-filled chewing gumcomposition which comprises enclosing a cavity containing a liquidcenter with an outer shell, wherein the outer shell comprises a gum basehaving an enhanced hydrophilic nature.
 50. A method for preparing acenter-filled chewing gum composition which comprises enclosing a cavitycontaining a liquid center with an outer shell, wherein the outer shellcomprises a chewing gum composition comprising:(A) a gum base having anenhanced hydrophilic nature present in an amount from about 40% to about85%, by weight of the chewing gum composition; and (B) a bulking agentpresent in an amount up to about 60%, by weight of the chewing gumcomposition.